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Advice For Downhill (steep) Hairpins/decreasing Rads


Orion
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I've never been really sure of the best way to deal with downhill hairpins and downhill decreasing rad bends, especially on a steep incline.

 

On a level track or even uphill I've improved immensely, but downhill my riding always seems to suffer and gets worse the steeper the drop into the bend.

 

Can anybody offer any advice?

 

O

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I've never been really sure of the best way to deal with downhill hairpins and downhill decreasing rad bends, especially on a steep incline.

 

On a level track or even uphill I've improved immensely, but downhill my riding always seems to suffer and gets worse the steeper the drop into the bend.

 

Can anybody offer any advice?

 

O

 

No one?

 

Guess I need to describe my problem in more detail - here goes:

 

I'm breaking as normal, hitting my turning point, leaning and "trying" to accelerate once I'm at the right angle. My problem is speed (real or perceived). I find myself running wide and end up trailing my back break right through the turn. Slow in - slow out; not acceptable.

 

Even looking through the bend as far as a I can doesn't seem to help me.

 

Added to this, once I hit the gas I'm struggling to progressively role on - find me regularly arguing with myself...never a good sign; but maybe neutral throttle is acceptable (since I'm going downhill) ???

 

;o(

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Hey Orion,

 

Yes. More detail. That's exactly what I was going to ask for. And, still...

 

You are still describing the circumstances and your actions in very general terms. I can make some general statements, but, anything more would require many assumptions on my part. And, honestly, I can't say anything at this point that isn't already covered in TOTW.

 

For your own benefit, I would recommend writing out on paper a very specific and detailed description of THE corner you are having difficulty with. Include all aspects including radius change, elevation change, fall line, camber relative to the inside of the corner or lack thereof, etc. I would recommend parking your bike and walking back and forth through this particular corner. Draw a picture. Or two. Or three. Draw your current line with reference points and actions. Draw a plan of what you think you should be doing. Brake points, turn points, line targets, eye targets, etc., etc., etc....

 

Get to know the corner. Make friends with it. Don't be a stranger to it and don't let it be a stranger to you.

 

Read Keith's articles on this site. That being said...

 

Yes, gravity will accelerate a bike going downhill. I agree that your throttle should be at least neutral. If not slightly cracked on to maintain your line. Try this at a speed well within your comfort zone (ie NOT dragging the rear brake). Keep riding thru the corner with proper form, doing the right thing, and when you can go thru consistently maintaining proper form (ie smoothly adding throttle, not rolling off or dragging the rear brake) over and over again, then try adding a little more speed each time. Getting in and freaking out and dragging the rear brake and running wide and going for the spare pair of underwear isn't going to improve anything, it will only reinforce your fear.

 

Get a copy of Twist of the Wrist and check out a school ASAP.

 

Cheers.

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  • 1 month later...

I've never been really sure of the best way to deal with downhill hairpins and downhill decreasing rad bends, especially on a steep incline.

 

On a level track or even uphill I've improved immensely, but downhill my riding always seems to suffer and gets worse the steeper the drop into the bend.

 

Can anybody offer any advice?

 

O

 

I used to feel uneasy in downhill turns as well and now I feel as confident as with any other turn. So I hope I can help. (On the most sever downhill mountain switchback turns, I may still not be able to throttle on through it, but there is a point where you are just no longer within the kind of conditions that the bike was designed to handle.)

 

1. First consider a fixed-radius downhill turn:

 

In superbike school the first lesson you learn is to roll on the throttle as soon as you lean in and keep rolling it on gently through the whole turn. You obviously know this already. The same is true for downhill turns. But, since you will have some added acceleration from gravity, you are obviously going to accelerate faster in a downhill turn, therefore you need to enter the turn slower. In my opinion it is just that simple. A bike is most stable under mild acceleration. However, the acceleration you get from gravity will not add any stability to the bike. That added stability only comes from that mild acceleration due to the bikes own power. So you are going to be adding up both acceleration from gravity and acceleration due to the throttle roll on. In sever downhill turns, I end up entering very slowly, but it is still fun because I come out fast and execute a smooth corner. I also find on downhill turns that I have to be more conscious about making sure to look through the turn.

 

2. Now consider the reducing radius turn:

 

My opinion is, save your throttle roll-on until the sharpest part of the turn. Obviously that is the point where you need the most stability, because that is where your lean angle will be the most severe. This is true downhill or not. If you try to roll-on the throttle through an entire long sweeping reducing radius turn, you'll have to go akwardly slow in the large radius portion of the turn and stupidly fast in the sharpest part. So just go through the first part off-throttle, you won't be leaned very low in this portion of the turn anyway, so you can get away with it, and you can even get away with some gentle front braking if you need to slow down a bit more for the approaching sharper part of the turn. The important thing is to understand that you do not have that added stability when off-throttle, and you are loading the front wheel, so it will step out if it runs over something slippery, so watch the surface carefully on public roads. Once you get the sharper part of the turn, lean in further and roll-on the throttle as usual. Don't begin your roll-on until you can roll it on and keep it on through the rest of the corner. Do not get into the situation of being leaned very low and still off-throttle.

 

3. And finally the reducing radius downhill turn:

 

Do same as any other reducing radious turn (number 2 above) but enter the sharpest part of the turn at a slower speed (number 1 above).

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  • 2 weeks later...

I've never been really sure of the best way to deal with downhill hairpins and downhill decreasing rad bends, especially on a steep incline.

 

On a level track or even uphill I've improved immensely, but downhill my riding always seems to suffer and gets worse the steeper the drop into the bend.

 

Can anybody offer any advice?

 

O

 

Orion,

 

Unless the hill is Really, really, really steep the bike slows when you roll off the gas. The secret to these turns is your turn point. If you make your final commitment to the turn too early, all of the bad things that are happening to you will continue to happen to you.

 

The basic idea of straightening out the turn means that you have chosen a turn in point that creates a constant radius turn for yourself. That means you must turn in later in most hairpins and ALL decreasing radius turns too straighten them out..

 

Turn in late enough and I'll bet that your problems disappear.

 

Keith

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  • 4 weeks later...

I have a similar issue, but I think it is mental. I'd love to know what others think.

 

I have a conceptual problem with downhill turns because I fear the front is going to be pushed past its traction limit because the bike is leaning forward/ as am I and the road is falling away. It is not an issue - in my mind- that there is to much weight, but to little - the road is falling away from the wheel. The last few turns at VIR threw me for a loop when I did Lvl 1 and 2. The fear of being able to get on the gas would result in me slowing down the entry speed and then being very conservative with the throttle.

 

The science of it would indicate that the front is not being over worked. The pitch of the hill is not going to change the weight distribution that much. Of all the places people crash at VIR, going downhill is generally not one of them. But, yet I have an issue with getting on the gas and shifting weight to the rear with a road that is falling away from the front. I'm guessing that this may be a survival instinct issue - I just don't feel safe pitched forward.

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I have a similar issue, but I think it is mental. I'd love to know what others think.

 

I have a conceptual problem with downhill turns because I fear the front is going to be pushed past its traction limit because the bike is leaning forward/ as am I and the road is falling away. It is not an issue - in my mind- that there is to much weight, but to little - the road is falling away from the wheel. The last few turns at VIR threw me for a loop when I did Lvl 1 and 2. The fear of being able to get on the gas would result in me slowing down the entry speed and then being very conservative with the throttle.

 

The science of it would indicate that the front is not being over worked. The pitch of the hill is not going to change the weight distribution that much. Of all the places people crash at VIR, going downhill is generally not one of them. But, yet I have an issue with getting on the gas and shifting weight to the rear with a road that is falling away from the front. I'm guessing that this may be a survival instinct issue - I just don't feel safe pitched forward.

 

I know exactly what you mean and it is a barrier. If you can start out my giving it a little gas, then stay with that for a while in a particular turn (on track) and then persuade yourself to add just a little more gas, eventually you can break through to more confidence in downhill corners.

 

As I said before, the line has to be right or it spoils your attempts to the turn inpoint and your apeex points should be consistant before you go out on a limb and spook yourlself.

 

Keith

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Could anyone explain the effect of uisng the back brake for adjusting the speed/lean angle through a turn

in particular the down hill/hairpin would seem to be a good place to use it if you need to lose speed when

leaned over without overloading the front tire. On the gas with a little rear brake should do the trick.

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